It is common for components, which are joined to one another by means of sintering, to comprise contact surfaces in the form of thin cover layers made of gold. For example, underlying layers that are prone to oxidation can be covered by means of such cover layers and thus be protected. Since, on the one hand, sinter layers, e.g., of silver, may have a high solubility and diffusivity of oxygen, and, on the other hand, gold may dissolve in silver in the course of time, there is a risk that the ground below a gold cover layer oxidizes over time. Experience has shown that a sinter layer easily loses grip on an oxide layer forming in this way underneath the sinter layer, putting the long-term stability of the sintered connection at risk.
To avoid such problems, gold layers, which turn out to be very thick with a thickness of at least 100 nm and thus also very expensive, have mostly been used. Alternatively, palladium is used as a cheaper noble metal variant, which is covered with a very thin gold layer having a thickness in the range of a few nanometers. Furthermore, it is also known to use thick silver layers for coverage. However, again an adhesive layer made of a noble metal is to be placed underneath a thick silver layer when porous silver sinter layers, which usually develop in a pressure-free sintering process, are used, for example, in order to suppress de-wetting of silver on a metal oxide layer developing on non-precious adhesive layers in the long run.